Foundries often include induction furnaces for melting metals. The induction furnace typically comprises an elongate, cylindrical crucible inside which the metal material is melted. The furnace must generate high temperatures, on the order of 2500 degrees Fahrenheit or more, to melt the metal, and therefore the inside of the crucible is typically lined with a refractory.
The metallic material which is added to the furnace is called a charge. The charge typically includes steel, pig iron, alloys, and returns. The returns typically make up 30 to 50 percent of the charge, and include previously formed members such as runners and gates used in molds. The various components of the charge material may be provided in a wide variety of shapes. The gates and runners of the returns, for example, are often provided in the form of the elongate shafts or bars. Other materials may be provided in generally spherical or arcuate shapes.
A transport device is typically used to deposit the charge into the crucible. A vibratory feeder, for example, typically has a hopper portion for receiving the returns, pig iron and other materials to be discharged into the crucible. The vibratory feeder advances the charge toward a front end of the feeder. A nosepiece located at the end of the vibratory feeder is positioned over the crucible and defines a chute for directing the charge into the crucible.
As the charge is transported toward the front end of the vibratory feeder, the returns and other components of the charge may shift and intertwine such that the charge bridges rather than drops through the chute to the crucible. Accordingly, conventional nosepieces typically have an open construction to allow access to the charge in case the charge bridges. It is common, for example, a conventional nosepiece to have a semi-circular chute. The open construction, however, does not limit the distance which the charge material travels away from the vibratory feeder as it is pushed over the chute. As a result, portions of the charge may impact a top edge of the crucible thereby damaging the crucible. The charge also may impact and damage the refractory liner of the crucible. The materials and labor required to replace a refractory liner often costs on the order of $10,000.00 or more. In addition, the furnace is not available for use during refractory replacement, which typically takes 3-5 days, resulting in a significant amount of down time for the furnace. Accordingly, there is a need for a nosepiece which accurately deposits a charge into a crucible without damaging the crucible.